Various input devices, such as a keypad, a jog dial, and a touch screen, have been used to control various functions of a vehicle. Recently, attempts have been made to apply a touch display apparatus to a cluster or an audio-video-navigation (AVN) system in order to improve a user's operating touch and a vehicle design. Research has been done on applying a rear surface projection type of touch display apparatus to curved surfaces in a vehicle. The rear surface projection type of touch display apparatus uses a projector which is disposed in a rear surface of a screen to project an image.
Conventional touch display apparatuses using infrared include a display device for displaying an image, an infrared irradiator for irradiating infrared rays to an image displaying part, and an infrared camera for sensing the infrared rays reflected from the image displaying part.
As the display apparatus included in the conventional touch display apparatus using infrared rays, a screen display apparatus for displaying an image on a screen by using a projector and a liquid crystal display (LCD) apparatus including a liquid crystal panel for displaying the image using a liquid crystal and a back light unit for irradiating light to the liquid crystal panel have been used.
However, if feedback is not provided to a user when the user operates the touch display apparatus, the user needs to keep an eye on the screen. As a result, in a case of the touch display apparatus mounted in the vehicle, if feedback corresponding to a touch is not provided, a driver's gaze may be distributed.
The conventional touch display apparatus provides tactile feedback using a motor or a piezoelectric element. However, in a case of using the motor, there are problems in that noise is generated according to a driving of the motor, and therefore marketability is deteriorated. In a case of using the piezoelectric element, the piezoelectric element should be made of a transparent material to use the projector. However, the cost is high for such transparent materials.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.